American school kids. Too young for the weight of the world to be on their shoulders but ripe for back pain because of overloaded backpacks. The University of California at San Diego gave kids backpacks ranging from empty to 26 pounds then used an MRI to scan their spines. The result? The heavier the bags the more disc compression, spine curvature and pain.

14-year-old Hebron High School volleyball player Micaela Spann carries everything from makeup to calculators in her backpack, not to mention at least seven books. Her backpack weighs nearly 30 pounds and she said it causes pain in her middle and lower back.

"With volleyball, with passing, since you are down so low so much it hurts during that and sometimes I have to take breaks," Said Micaela.

Baylor- Carrollton pediatrician Dr. Monica Beamer isn't surprised and said heavy backpacks are a growing problem.

"They are having back pain and they just don't know what it's being caused by, they're not sleeping well at night and that caused problems with attitude during the day, so it's not just a back problem, it's an all over problem," Said Dr. Beamer.

Micaela carries two bags, her backpack and gym bag. She says most kids do it because going to the locker in between classes is a hassle. Single strap messenger bags are also popular, but Dr. Beamer says they're no better than backpacks. Another recent study indicated that 60% of childhood back problems are caused by heavy backpacks.

Dr. Beamer said kids may face a lifetime of back issues.

"These kids have posture problems, these kids go around carrying these backpacks and guess what? When they take those backpacks off they're still going to stand that way, it just becomes engrained and that pain becomes pretty permanent," Said Dr. Beamer.

As for Micaela, she said the book related back pain is chapter of life she's just have to live with.

"I figure that it will get better and if it gets too bad, I'll just come to the doctor," Said Micaela.

Dr. Beamer suggests that kids lighter their load by only carrying books they'll need that day and carry the backpack on both shoulders to spread the weight around. Better yet, use a rolling backpack to reduce the entire load.